what would you list as 'essential files' to save elsewhere?
Documents
Pictures
Video
Browser Bookmarks (Favourites)
Email contact list/address-book
Login/Passwords for forums/shopping/banking etc.
Settings (POP login/passwords) for email/internet accesss
Software you have bought and paid-for as a download (i.e Not on CD)
It is also possible to save all previous e.mail messages and reload them to your email client (later) after doing a clean install.
*Some brands of PC`s aren`t supplied with a Windows O/S disc; they have a restore/repair utilty disc supplied by the manufacturer, which access` a copy of Windows Operating System stored on a small discrete partition on the HDD.
Because of this, you must be careful not to alter or remove any partition on your HDD without checking -first if it is required by the computer to complete a 'clean install'....Computer manual would have all the 'Gen' on the above.
